sys/sys/gmon.h

   1 /*-
   2  * Copyright (c) 1982, 1986, 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)gmon.h      8.2 (Berkeley) 1/4/94
  30  * $FreeBSD: src/sys/sys/gmon.h,v 1.15 1999/08/28 00:51:45 peter Exp $
  31  */
  32
  33 #ifndef _SYS_GMON_H_
  34 #define _SYS_GMON_H_
  35
  36 #include <sys/cdefs.h>
  37
  38 #include <machine/profile.h>
  39
  40 /*
  41  * Structure prepended to gmon.out profiling data file.
  42  */
  43 struct gmonhdr {
  44         u_long  lpc;            /* base pc address of sample buffer */
  45         u_long  hpc;            /* max pc address of sampled buffer */
  46         int     ncnt;           /* size of sample buffer (plus this header) */
  47         int     version;        /* version number */
  48         int     profrate;       /* profiling clock rate */
  49         int     spare[3];       /* reserved */
  50         /* XXX should record counter size and density */
  51 };
  52 #define GMONVERSION     0x00051879
  53
  54 #define HISTCOUNTER     unsigned short
  55
  56 /*
  57  * Fraction of text space to allocate for histogram counters.
  58  * We allocate counters at the same or higher density as function
  59  * addresses, so that each counter belongs to a unique function.
  60  * A lower density of counters would give less resolution but a
  61  * higher density would be wasted.
  62  */
  63 #define HISTFRACTION    (FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER) == 0 \
  64                          ? 1 : FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER))
  65
  66 /*
  67  * Fraction of text space to allocate for from hash buckets.
  68  * The value of HASHFRACTION is based on the minimum number of bytes
  69  * of separation between two subroutine call points in the object code.
  70  * Given MIN_SUBR_SEPARATION bytes of separation the value of
  71  * HASHFRACTION is calculated as:
  72  *
  73  *      HASHFRACTION = MIN_SUBR_SEPARATION / (2 * sizeof(short) - 1);
  74  *
  75  * For example, on the VAX, the shortest two call sequence is:
  76  *
  77  *      calls   $0,(r0)
  78  *      calls   $0,(r0)
  79  *
  80  * which is separated by only three bytes, thus HASHFRACTION is
  81  * calculated as:
  82  *
  83  *      HASHFRACTION = 3 / (2 * 2 - 1) = 1
  84  *
  85  * Note that the division above rounds down, thus if MIN_SUBR_FRACTION
  86  * is less than three, this algorithm will not work!
  87  *
  88  * In practice, however, call instructions are rarely at a minimal
  89  * distance.  Hence, we will define HASHFRACTION to be 2 across all
  90  * architectures.  This saves a reasonable amount of space for
  91  * profiling data structures without (in practice) sacrificing
  92  * any granularity.
  93  */
  94 /*
  95  * XXX I think the above analysis completely misses the point.  I think
  96  * the point is that addresses in different functions must hash to
  97  * different values.  Since the hash is essentially division by
  98  * sizeof(unsigned short), the correct formula is:
  99  *
 100  *      HASHFRACTION = MIN_FUNCTION_ALIGNMENT / sizeof(unsigned short)
 101  *
 102  * Note that he unsigned short here has nothing to do with the one for
 103  * HISTFRACTION.
 104  *
 105  * Hash collisions from a two call sequence don't matter.  They get
 106  * handled like collisions for calls to different addresses from the
 107  * same address through a function pointer.
 108  */
 109 #define HASHFRACTION    (FUNCTION_ALIGNMENT / sizeof(unsigned short) == 0 \
 110                          ? 1 : FUNCTION_ALIGNMENT / sizeof(unsigned short))
 111
 112 /*
 113  * percent of text space to allocate for tostructs with a minimum.
 114  */
 115 #define ARCDENSITY      2
 116 #define MINARCS         50
 117
 118 /*
 119  * Limit on the number of arcs to so that arc numbers can be stored in
 120  * `*froms' and stored and incremented without overflow in links.
 121  */
 122 #define MAXARCS         (((u_long)1 << (8 * sizeof(u_short))) - 2)
 123
 124 struct tostruct {
 125         u_long  selfpc;
 126         long    count;
 127         u_short link;
 128         u_short pad;
 129 };
 130
 131 /*
 132  * a raw arc, with pointers to the calling site and
 133  * the called site and a count.
 134  */
 135 struct rawarc {
 136         u_long  raw_frompc;
 137         u_long  raw_selfpc;
 138         long    raw_count;
 139 };
 140
 141 /*
 142  * general rounding functions.
 143  */
 144 #define ROUNDDOWN(x,y)  rounddown(x,y)
 145 #define ROUNDUP(x,y)    roundup(x,y)
 146
 147 /*
 148  * The profiling data structures are housed in this structure.
 149  */
 150 struct gmonparam {
 151         int             state;
 152         HISTCOUNTER     *kcount;
 153         u_long          kcountsize;
 154         u_short         *froms;
 155         u_long          fromssize;
 156         struct tostruct *tos;
 157         u_long          tossize;
 158         long            tolimit;
 159         u_long          lowpc;
 160         u_long          highpc;
 161         u_long          textsize;
 162         u_long          hashfraction;
 163         int             profrate;       /* XXX wrong type to match gmonhdr */
 164         HISTCOUNTER     *cputime_count;
 165         int             cputime_overhead;
 166         HISTCOUNTER     *mcount_count;
 167         int             mcount_overhead;
 168         int             mcount_post_overhead;
 169         int             mcount_pre_overhead;
 170         HISTCOUNTER     *mexitcount_count;
 171         int             mexitcount_overhead;
 172         int             mexitcount_post_overhead;
 173         int             mexitcount_pre_overhead;
 174 };
 175 extern struct gmonparam _gmonparam;
 176
 177 /*
 178  * Possible states of profiling.
 179  */
 180 #define GMON_PROF_ON    0
 181 #define GMON_PROF_BUSY  1
 182 #define GMON_PROF_ERROR 2
 183 #define GMON_PROF_OFF   3
 184 #define GMON_PROF_HIRES 4
 185
 186 __BEGIN_DECLS
 187 void    moncontrol(int);
 188 void    monstartup(u_long, u_long);
 189 __END_DECLS
 190
 191 #endif /* !_SYS_GMON_H_ */